Indicator for pressure-gages.



R. E. FIELDS.

INDICATOR FOR PRESSURE GAGES.

APPLICATION FILED JAN.16, 1909.

Patented July 19,1910.

Wikwwoeo ROBERT E. FIELDS, OF FORT WORTH, TEXAS.

INDICATOR FOR PRESSURE-GAGES.-

Patented July 19, 1910.

' Application filed January 16, 1909. Serial No. 472,641.

T 0 all whom it may concern:

Be it known that I, ROBERT E. FIELDS, a citizen of the United States,residing at Fort Worth, in the county of Tarrant and State of Texas,have invented certain new and useful Improvements in Indicators forPressure-Gages, of which the following is a specification.

This invention relates to pressure gages and more particularly to meansfor making the gages indicate in a more striking manner the changetaking place in the pressure and whether the pressure is decreasing orincreasing, and the object is to provide the indicators of gages withauxiliary indicators by which the space traversed by a main indicator ismultiplied by the auxiliary indicator so that a slight movement of themain indicator will cause a much larger movement of the auxiliaryindicator.

With the gages in use, the indicator must traverse practically a spacewhich indicates a change of five pounds of'pressure before it will beordinarily observed and the observer has to charge his memory with thereading previously made. By the time a decrease of five pounds ofpressure is noted, a considerable headway is gained and still morepressure will be lost because the fireman must put in fresh coal or fueland this will require to be ignited before it will produce heat and thefresh fuel will cause loss of heat for a few minutes. The effect of suchchanges on the steam boilers is enormous. The contraction and expansiondue to the falland rise of pressure caused by variations in heat ruinboilers and break,

' stay-bolts. The disadvantage of the-indicators in useisthat they donot sufficiently warn the firemen and engineers of the enormous effectof losing as much as five pounds of pressure. It is desirable-to show ina more striking manner the changes taking place. The engineer or thefireman should know instantly when the pressure commences to change.

The object of this invention is to remedy the defects of the gages inuse.

Other objects and advantages will be fully explained in the followingdescription and the invention will be more particularly pointed out inthe claims.

Reference is had to the accompanying drawings which form a part of thisappli cation and specification.

Figure 1 is a face of an ordinary ressure gage with the auxiliaryindicator an an are attached to the indicator of the gage. Fig. 2 is asimilar View of a gage, showing a variation of the manner of mountingthe auxiliary indicator. Fig. 3 is a side elevation of the indicatorsshown in Fig. 1'. Fig. 4 is a similar view to Fig. 3, but showin avariation in the construction of the friction device of the auxiliaryindicator.

Similar characters of reference are used to indicate the same partsthroughout the several views.

The dial of an ordinary pressure gage is shown in the drawings. The dialplate 1 is provided with the usual degree scale and an indicator 2mounted on an arbor 3. An auxiliary indicator 4 is pivotally connectedto the indicator 2, preferably on the under-' side thereof. An are 5 isalso attached to the underside of the indicator 2. This are is suitablymarked with lines into spaces over which the point of the indicator 4moves in operation. One end of the indicator 4 has a friction pad 6attached thereto to move on the face of the dial plate 1.

The construction of the device which bears against the face of the plate1 may be varied. F ig. 4 shows the friction device in the form of acone-shaped roller 7. It is not necessary that the auxiliary indicatorshould be mounted on the main indicator 2, as the auxiliary indicatormay be mounted on an arm 8 which is rigid with the indicator 2, as shownin Fig. 2. The friction bearing 6 or 7 will control the movement of thepoint of the indicator 4. When the main indicator moves the frictionbearing will trail behind the main indicator 2. The are 5 may be madeany suitable size and the pointer of the auxiliary indicator 4 may be ofany suitable length. The drawings show the gage provided with spaceswhich indicate five pounds of pressure and the are 5 shows five spaces,each of which spaces is equal to a five pound space on the gage dial sothat the space on the arc is multiplied five times, or to. state thematter in different words, while pointer of the main indicator moves onequarter of an inch space on the gage dial scale, the pointer 4 of theauxiliary indicator will move five quarter inch spaces on the arc 5. I

The pointer 4 is intended to move only over the arc 5. When the pressureis rising the hand or indicator 2 turns in the direction of a clockhand. When the pressure is falling the indicator 2 moves in the oppositedirection to that of a clock hand. When the pressure is rising theauxiliary indicator 4: will move in front of the indicator 2' and thefriction pad 6 will trail behind the indicator 2. As a matter of fact,the friction pad 6 will ordinarily move very little since the variationof the pressure is not ordinarily more than ten or fifteen pounds andnot often that much. With a variation of five pounds the movement of thepad, if perceptible at all, will be very slight. The auxiliary indicatorserves to show whether the pressure is rising or falling. When thepressure is falling the indicator 2 moves in a direction opposlte tothat of a clock hand and the indicator I will move in front of indicator2 and the pad 6 will trail behind the indicator 2. The pad 6 actssomewhat as a pivot.

In Fig. 1 of the drawing the full lines indicate the position of theauxiliary indicator at starting and the dotted lines indicate theposition of the auxiliary indicator relative to the main indicator andthe are 5 after the auxiliary indicator has reached its limit. Theposition of the auxiliary indicator may. be changed by connecting thesame with the main indicator near the arbor of the main indicator andplacing the arc toward the end of the main indicator. The pivotalconnection of the auxiliary indicator with the main indicator may bevaried. The bearing surface of the auxiliary indicator against the faceof the dial plate may consist of any material or device which willefiect the turning of the auxiliary indicator when the main indicatormoves.

The proportionof the spaces of the are 5 to the spaces of the main dialmay be increased or decreased. The main indicator carries the auxiliaryindicator and as the main indicator moves the friction bearing of theauxiliary indicator presses against the face of the dial plate. Thiswill cause the pointer of the auxiliary indicator to move over the are5. In this manner the slightest change of pressure can be seen at aglance by a fireman or engineer or other operator, and the observer willknow by the position of the auxiliary indicator on one side or the otherof the main indicator whether the pressure is increasing or decreasing.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent, is,-

1. In a pressure gage provided with a dial and'a main indicator movingabout said dial; an auxiliary indicator pivotally connected to andcooperating with said mainindicator, an are attached to said mainindicator, and means for causing said auxiliary indicator to moverelative to said arc.

2. In a pressure gage provided with a dial and a main indicator; anauxiliary indicator pivotally connected to and cooperatin with said mainindicator, a graduated are attached to said main indicator, and meanscontacting with said dial and carried by said auxiliary indicator forcausing the same to move relative to said are.

3. In a pressure gage provided with a dial and a main indicator; an areattached to said indicator and carried thereby and an auxiliaryindicator pivotally connected with said main indicator and cooperatingwith said are and having a friction bearing adapted to contact with saiddial.

4. In a pressure gage provided with a dial and a main indicator; anauxiliary indicator pivotally connected to said main indicator, an arecooperating with said auxiliary indicator to show an increased number ofspaces as compared with the spaces indicated by said main indicator, andmeans cooperating with said main indicator to cause the movement of theauxiliary indicator relative to said are. 1

5. In a pressure gage provided with a dial and a main indicator; anauxiliary indicator actuated by said main indicator, an arc moving withsaid main indicator and cooperating with said auxiliary indicator toshow an increased number of spaces as compared with the spaces indicatedby said main indicator, and means cooperating with said main indicatorto cause the movement of said auxiliary indicator relative to said are.

6. In a pressure gage provided with a dial and a main indicator movingabout said dial, an arc moving with said main indicator, and anauxiliary indicator actuated by said main indicator and cooperating withsaid moving arc.

In testimony whereof, I set my hand in the presence of two witnesses,this 6th day of January, 1909.

ROBERT E. FIELDS. Witnesses:

A. L. JAcKsoN, J. W. STITT.

